Plasmonic enhancement of second-harmonic generation of dielectric layer embedded in metal-dielectric-metal structure

• Published in: Journal of applied physics Vol. 123; no. 12
• Main Authors: Kang, Byungjun, Imakita, Kenji, Fujii, Minoru, Hayashi, Shinji
• Format: Journal Article
• Language: English
• Published: 28.03.2018
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.5018239

The enhancement of second-harmonic generation from a dielectric layer embedded in a metal-dielectric-metal structure upon excitation of surface plasmon polaritons is demonstrated experimentally. The metal-dielectric-metal structure consisting of a Gex(SiO2)1–x layer sandwiched by two Ag layers was prepared, and the surface plasmon polaritons were excited in an attenuated total reflection geometry. The measured attenuated total reflection spectra exhibited two reflection dips corresponding to the excitation of two different surface plasmon polariton modes. Strong second-harmonic signals were observed under the excitation of these surface plasmon polariton modes. The results demonstrate that the second-harmonic intensity of the Gex(SiO2)1–x layer is highly enhanced relative to that of the single layer deposited on a substrate. Under the excitation of one of the two surface plasmon polariton modes, the estimated enhancement factor falls in a range between 39.9 and 171, while under the excitation of the other surface plasmon polariton mode, it falls in a range between 3.96 and 84.6.